Chinatown 5th Avenue Shallow Diagonal Station

CID 5th Avenue Shallow Diagonal map from Sound Transit

The Chinatown 5th Avenue Shallow Diagonal (labeled CID-2a) station has returned as a potential implementation. Most notably it appears to be the only CID station alternative remaining that is both constructible at a reasonable cost and has all three Link lines at one convenient place for transfers. The other 5th Avenue shallow alternatives had community objections due to construction impacts, 4th Avenue shallow alternative faced construction challenges next to BNSF tracks, and finally the currently Sound Transit Board preferred' CID N/S alternative forces one to transfer at Pioneer Square.

There was relatively little discussion on the 5th Avenue Shallow Diagonal alternative when all the 5th Avenue alternatives were sidelined by community concerns in 2022-2023. It's been quite some time since the diagrams were released in 2022 and many of the diagrams were in a 100+ page pdf so below is a brief recap with more details from the WSBLE Appendix J Ballard drawings. Additionally how easy or hard to transfer between the two lines will be discussed as well.

5th Avenue Shallow Alternative Diagonal Site Map

Above is the detailed station diagram with the main escalators and elevators in the main station building at the south-east corner of 5th Ave S & S Jackson St.

Section C and Section D facing south

The station platform would be ~80 feet depth underground (the ground elevation is 47 feet and the station platform elevation is -34 feet). The underground station would serve the 1 Line (from SeaTac to Ballard).

5th Avenue Shallow Alternative Diagonal Station Site Section A facing south and Section B facing east

1 Line passengers from SeaTac transferring to the 2 Line or 3 Line (from Redmond or West Seattle to Lynnwood) would:

• (1) First head up the escalators from the station platform to the mezzanine.
• (2) Then they would head up another 2 flights of escalators
• (3) Finally walk the pedestrian under-crossing to reach the northbound 2 Line or 3 Line heading to Lynnwood.

It is a total of ~50 vertical feet from the 1 Line station platform to the 2 Line or 3 Line station platform. (This is the existing CID northbound station platform)

Diagonal Station diagram annotated with pedestrian route to reach Southbound Line 3

Those transferring to the southbound 2 Line or 3 Line heading to Redmond or West Seattle would need to additionally:

• (4) Head up another flight of escalators to the Chinatown Station Plaza
• (5) Walk across the plaza to the east
• (6) Head back down the escalators to reach to reach the southbound 2 Line heading to Redmond.

A direct pedestrian under-crossing to remove traveling up and down to reach the southbound 2 Line or 3 Line station platform is prohibitively hard to construct given the existing station piles.

Transfer Patterns

One moderate consolation for the imperfect transfer setup is that the most common transfers patterns will usually not encounter the more complicated setup. The northbound passengers from SeaTac to Lynnwood will head up the three escalators and not need to cross the plaza. The southbound passengers from Lynnwood to SeaTac will have to cross the plaza but the rest of the 5 sets of escalators will be heading down rather than up, which is generally easier.

Passengers from Redmond/West Seattle (northbound existing chinatown station) to Ballard would just need to head down 3 sets of escalators without crossing the station plaza.

Unfortunately, passengers heading from SeaTac to Redmond (southbound existing chinatown station platform) would have the hardest time as outlined above with the most vertical feet to climb. Those heading to West Seattle can transfer earlier and much easier at the SODO station with just 2 sets of escalators rather than 5 sets of escalators.

Comparison to CID 5th Ave Shallow (Regular)

The 5th Avenue Shallow (Regular) alternative has the northbound and southbound 1 Line stations stacked on top of each other instead of side by side. Generally the transfer time and complexity is about the same as the diagonal alternative.

5th Avenue Shallow (Regular) Alternative property takings from station planning report

The 5th Avenue Shallow alternative will demolish most of the 5th Ave/S Jackson St southeast block. Most of the block's western half will be demolished. For the block's eastern half the American Hotel Hostel will remain in place but the Bank of America and it's parking lot will be demolished.

Originally 5th Avenue Shallow Diagonal alternative required the same and more property takings than the regular 5th Avenue Shallow alternative described above. The diagonal alternative had to also remove the American Hotel Hostel. However, with the further additional studies Sound Transit has found removing that building is no longer necessary.

More details in Appendix L Chapter 4 L4.1

The two alternatives other construction impacts are detailed more in Chapter 6 DEIS.

Road impacts:

• Regular: Full closure of 5th Avenue South during construction for 9 months
  between South Weller Street and South Jackson Street would result in traffic diversion, including buses, into Pioneer Square and ChinatownInternational District. Additional partial closures on this street for 2.5 years.
• Diagonal: The diagonal station configuration would avoid full closure of 5th Avenue South and would not affect the intersection of this road and South Jackson Street. It would avoid the trolley bus relocation and impacts to Seattle Streetcar operations during construction.

Construction time:

• Regular: construction in the station area for 5th avenue shallow alternative would take approximately 8 to 9 years
• Diagonal: construction in the station area for the diagonal station configuration would take approximately 5 to 6 years

Comparison to CID N/S alternativeTransfer Comparison for CID-North (Midtown James Street) Midtown James Street Station diagram

The new CID-North* station will shift the Midtown station south next to the existing Pioneer Square station. Generally the vertical climb is around the same (don't have exact diagrams to calculate), but one will now need to walk across a ~350 feet underground passage way to reach the other station.

*now called Midtown James Street Station but has changed names twice already.

Walking to areas to CID-South (Dearborn Street)

The CID-South station or Dearborn Street" alternative will not serve as a major transfer point anymore as it will only have Line 1 (from SeaTac to Ballard) but not Line 2 or Line 3. It'd still serve as a major station for those in Chinatown heading to/from Rainier Valley, SeaTac and beyond.

Table of walking time to nearest 1 Line (SeaTac to Ballard) station

Above is a table comparing the 5th Ave Shallow Diagonal alternative to the 4th Ave Shallow and the CID N/S ones. The number represents minutes with the walk times to the closest 1 Line (SeaTac to Ballard) Station approximated based on an example walking route and based on average walk speed of 4ft/sec. Includes walk to either CID or Midtown stations